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What is a filegroup?
The filegroup contains the primary data file and any secondary files that aren’t put into other filegroups. User-defined filegroups can be created to group data files together for administrative, data allocation, and placement purposes.
What is secondary data file in SQL Server?
Secondary Data Files are data files that hold all data that do not belong in the Primary Data File. Data that doesn’t go into the Primary Data File is told to do so and set in a setting in SQL Server. Secondary Files are optional. These files should have a . ndf extension.
What is the purpose of secondary data file?
Secondary data file OR NDF file Secondary data files are useful when we want to stripe the data across multiple drives of the database server. For example, if you want to keep the tables on X drive and indexes on Y drive, then you can keep the tables on the primary data file and indexes on the secondary data file.
How to move a table to a secondary filegroup?
Move the tables to the secondary filegroup by moving the clustered index without the primary key. A secondary filegroup can be created using T-SQL OR using the Add file up wizard from SQL Server Management Studio. To add a filegroup using SSMS, open SSMS and select a database where a file group needs to be created.
When to create secondary datafiles and filegroups?
When we create a new database, we can create secondary datafiles and filegroups. Adding secondary data files helps to improve the performance. It can be created on different disk drives or separate disk partitions that reduces IO wait and read-write latency. It is recommended to keep tables and indexes in separate filegroups.
Can a database have more than one filegroup?
A filegroup works as a logical container for datafiles. One filegroup can have multiple data files. Now, let’s start with creating a SQL Server database with three data files in one filegroup and a log file.
How are data files grouped in SQL Server?
Transaction Log File s: The T-Logs files log all the transaction performed to recover the database. The Log file extension in .ldf. As I mentioned above, data files can be grouped in a filegroup. While SQL Server is being installed, it creates the Primary filegroup that has a primary data file. Secondary filegroups are user-defined.